The present invention relates to improvements in fluidic oscillators and particularly to a novel fluidic oscillator capable of providing a dynamic output flow of a broad range of properties which is obtainable by simple design variations and which can be further readily controlled during operation by appropriate adjustment means to achieve extensive performance flexibility, thus facilitating a wide variety of uses.
Fluidic oscillators and their uses as fluidic circuit components are well known. Fluidic oscillators providing dynamic spray or flow patterns issuing into ambient environment have been utilized in such manner in: shower heads, as described in my U.S. Pat. No. 3,563,462; in lawn sprinklers, as described in U.S. Pat. No. 3,432,102; in decorative fountains, as described in U.S. Pat. No. 3,595,479; in oral irrigators and other cleaning apparatus, as described in U.S. Pat. No. 3,468,325; (also see U.S. Pat. Nos. 3,507,275 and 4,052,002, etc.). Most of these oscillators are constructed to produce outflow patterns which are suitable only for use in the specific apparatus for which they were designed and lack flexibility and adjustability for use in other applications. In most applications for prior art oscillators it has been found that performance is adversely affected by relatively small dimensional variations in the oscillator passages and chamber. It has also been found that most prior art oscillators require configurations of relatively large dimensions to satisfy particular performance requirements such that they are barred from many uses by practical size restrictions. Furthermore, most prior art oscillators have not had the capability for extensive in-operation adjustments of performance characteristics to fulfill numerous uses necessitating such adjustment capabilities.
Many prior art fluidic devices, such as in U.S. Pat. Nos. 3,016,066 and 3,266,508, have relied in operation on well established fluidic principles, such as the Coanda effect. It is, in my opinion, this reliance on such well-known effects which has brought about the aforementioned limitations and disadvantages.
It is an object of the present invention to provide a fluidic oscillator which functions largely on different principles than previous fluidic oscillators and, therefore, overcomes the aforementioned limitations and disadvantages, and provides capabilities hitherto unavailable to meet application requirements for which prior art fluidic oscillators have not been suited.
It is another object of the present invention to provide a fluidic oscillator whose outflow pattern performance can be varied over broad ranges by simple design measures.
It is yet another object of the present invention to provide a fluidic oscillator which is relatively insensitive to dimensional manufacturing tolerances and dimensional variations resulting from its operation.
It is a further object of the present invention to provide a fluidic oscillator of relatively small dimensions to meet practical size restrictions of many applications. For example, where as most prior art fluidic oscillators require, for satisfactory functioning, lengths, between the feed-in supply fluid and the final outlet opening, of at least 10 (but more often 12 to 20 and in some cases as much as 30) times the respective supply feed-in nozzle widths, the present invention fluidic oscillator operates already with such relative lengths of as little as 5. Similarly, whereas most prior art fluidic oscillators require relative widths for the total channel configuration of at least 7 or more, the present invention oscillator configuration spans a relative width of 5 or less in many applications. One can readily appreciate the application advantages offered by such practical size reductions in the total oscillator configuration area to about one half or one third.
It is yet another object of the present invention to provide a fluidic oscillator allowing and facilitating extensive adjustments of performance characteristics over broad ranges during operation. Oscillation frequency and angle of output flow sweep pattern and, therefore, also such dependent characteristics as waveform, dispersal distribution, velocity, etc. may be adjusted by simple means such that performance can be varied and adapted to changing requirements during operation. Furthermore, it is also an object of the present invention to provide a fluidic oscillator whose performance may be adjusted or modulated continuously in the aforementioned characteristics by externally applied fluid control flow pressure signals. By way of an example, tests have been performed with experimental models of fluidic oscillators of the present invention, which have shown a frequency adjustment range of over one octave and an output sweep angle adjustment range from almost zero degress to over ninety degrees by application of an external fluid pressure flow to the oscillator control input connection with control pressure ranging between zero gage (no control flow) and the same pressure as supplied to the oscillator fluid power input. Additionally, inertance adjustments of the fluid inertance conduit of the oscillator have shown practical continuous control over oscillation frequency during operation over several octaves.
It is still another object of the present invention to provide arrays of two or more similar fluidic oscillators capable of being accurately synchronized with each other in any desired phase relationship by means of appropriate simple fluid conduit interconnections between such oscillators.
It is further an object of the present invention to provide fluidic oscillators for use in shower heads to provide dispersal of water flow into suitable spray and/or massaging and improved cleansing effects due to the cyclically repetitive flow impact forces on body surfaces, to further provide shower heads including fluidic oscillators for the aforementioned purposes, wherein oscillation frequency and spray angle are adjustable over broad ranges, and wherein the oscillators, if more than one are used, are synchronized with each other, and wherein manual controls are provided for such adjustments, and wherein the shower head has manually settable valving means for the mode selection of conventional steady spray or oscillator generated spray and massaging effects or any combination thereof.